Distance Scanner - Low Cost Walking Aid for the Blind

I got the time to work on arduino and put up a small project to aid Blind people navigate through obstacles. There are many attempts made by the arduino community to accomplish this but most of them used motors, servo motors to give feedback. But Blind people have to get used to different inputs they get from these devices and driving motor requires a lot of battery power, thus users might have to end up changing batteries frequently.

Furthermore many Blind use sound which comes from tapping the White cane to navigate through obstacles so sound is something that they are already familiar with.

My approach uses a Ultrasonic Ping Sensor and a Buzzer to notify the Blind person who wears it with a Buzzing sound. Items required are;

1. Arduino (Any Model)
2. Ultrasonic Ping Sensor
3. Buzzer or Piezo Speaker
4. Jumper Cables

Arduino Sketch Source code is below 

/* 
  Distance Scanner 
  By Shazin Sadakath
*/

#define BUZZER 10

int URPWM = 3; 
int URTRIG=5; 

int minDistanceCm = 50;

unsigned int Distance=0;
uint8_t EnPwmCmd[4]={0x44,0x02,0xbb,0x01};    
 
void setup(){                                 
 
    pinMode(URTRIG,OUTPUT);                   
  digitalWrite(URTRIG,HIGH);                  
  
  pinMode(URPWM, INPUT);                      
    
  pinMode(BUZZER, OUTPUT);
}
 
void loop()
{
 digitalWrite(URTRIG, LOW);
 digitalWrite(URTRIG, HIGH);               
     
 unsigned long DistanceMeasured=pulseIn(URPWM,LOW);
     
 if(DistanceMeasured==50000){              
     // Invalid    
 }else{
     Distance=DistanceMeasured/50;           
 }
 delay(20);
 buzzBasedOnDistance();
}                      

void buzzBasedOnDistance() {
  int far = Distance - minDistanceCm;
  if(far <= 0) {
    digitalWrite(BUZZER, 200); 
  } else {
    digitalWrite(BUZZER, 0);
  }
}

There is a configurable minimum distance threshold and when objects get closer than that the buzzer makes the noise so that obstacle can be avoided. Check the video below for a small demonstration.




The USB cable is only used for Power. It can be replaced with a battery pack powering the arduino.

Constructive criticism is always welcome!